The Marine Corps MOS 6423 is for Aviation Electronic Microminiature/Instrument and Cable Repair Technicians. These technicians inspect, test, maintain, and repair:
Modules
Cards
Printed-circuit boards
Cables
Instruments
Miniature and microminiature components
They also perform corrosion control.
The Marine Corps MOS 6423 is also known as Aviation Electronic Micro/miniature Component and Cable Repair Technician, IMA.